In situ electrochemical characterization of bioremediation microbial processes

我的研究项目使用现场传感器测量来表征和监测具有环境意义的微生物过程。微生物过程控制着地球上所有地方的环境地球化学，微生物在隔离和修复许多类型的环境污染物方面发挥着关键作用。结石营养细菌--那些使用铁、S和氮等无机代谢底物的细菌--在生物修复中特别重要，因为它们推动生物地球化学反应，可以减弱、转化或释放污染物，如锰、砷和汞。它们的重要性使得详细和细致入微地了解结石营养微生物如何循环无机代谢底物对于有效的生物修复策略至关重要。这一研究方法提供了以前无法获取的关于复杂自然微生物群落中的地球化学循环和能量传递的基本方面的信息。电极通常被用来监测环境系统中与微生物相关的地球化学参数，包括pH、氧化还原电位、电导率、溶解氧、温度和溶解离子(即氨、硫化氢)的浓度。我最近的工作表明，除了记录实时的物理化学环境外，电极还记录了以前无法获取的关于正在进行的动态生物地球化学过程的信息。电极时间序列记录了代谢底物运动的实时微生物中介。对这些时间序列的分维分析表明，同一生物地球化学反应的不同地球化学路径产生的时间序列具有不同的分维特征。这区分了生物和非生物对正在进行的生物地球化学过程的贡献。我的研究计划的短期目标是描述具有生物修复兴趣的岩石营养代谢途径，包括铁和砷氧化(酸性矿山废水)、锰氧化(弗雷德里克顿市政饮用水)和蓝藻(光合作用)毒素产生(地表水中的微囊藻毒素和类毒素)。这将通过基于实验室的微观实验来完成。建立在对个体途径研究的基础上的长期目标是将这些方法应用于天然(原始和受污染的)微生物群落。在现场同时区分和测量生物地球化学反应的能力是现有努力的一项重大创新，这些努力旨在开发基于传感器的低成本环境监测战略，并扩展成熟的生物电修复方法，以收集关于生物修复微生物群落功能的更多信息。使用传感器获取特定于过程的生物地球化学信息，减少了亲自监测地点的需要，并提供了更好的空间和时间分辨率数据，以限制生物地球化学过程。

My research program uses in situ sensor measurements to characterize and monitor microbial processes of environmental significance. Microbial processes control environmental geochemistry everywhere on Earth, and microbes perform critical functions in sequestering and remediating many types of environmental contaminants. Lithotrophic bacteria-those that use inorganic metabolic substrates such as Fe, S, and N-are particularly important in bioremediation, because they drive biogeochemical reactions that can attenuate, transform, or release contaminants such as Mn, As, and Hg. Their importance makes detailed and nuanced understanding of how lithotrophic microbes cycle inorganic metabolic substrates critical to effective bioremediation strategies. This research approach provides previously inaccessible information about the fundamental aspects of geochemical cycling and energy transduction in complex natural microbial communities. Electrodes are often used to monitor microbially-relevant geochemical parameters in environmental systems, including pH, oxidation-reduction potential, conductivity, dissolved oxygen, temperature, and concentrations of dissolved ions (i.e., ammonia, hydrogen sulfide). My recent work indicates that, in addition to recording the real-time physicochemical environment, electrodes record previously inaccessible information about ongoing dynamic biogeochemical processes. Electrode time series record real-time microbial mediation of the motion of metabolic substrates. Fractal analysis of these time series shows that time series arising from different geochemical pathways of the same biogeochemical reaction have characteristic, different fractal dimensions. This distinguishes biological and abiotic contributions to ongoing biogeochemical processes. The short-term goals of my research program are to characterize lithotrophic metabolic pathways of bioremediation interest, including Fe- and As-oxidation (acid mine drainage), Mn-oxidation (Fredericton municipal drinking water), and cyanobacterial (photosynthetic) toxin production (microcystin and anatoxin in surface water bodies). This will be accomplished with lab-based microcosm experiments. The long-term goal, building on the study of individual pathways, is the application of these methods to natural (pristine and contaminated) microbial communities. The capability to distinguish and measure biogeochemical reactions simultaneously in situ represents a major innovation on existing efforts to develop low-cost sensor-based environmental monitoring strategies, as well as extending well-established bioelectrical remediation methods to collect more information about the functions of bioremediation microbial communities. Using sensors to obtain process-specific biogeochemical information reduces the need for in-person monitoring of sites, as well as providing better spatially and temporally resolved data to constrain biogeochemical processes.